Hey this is the HVC school podcast, I'm Brian. This is the podcast that helps you remember some stuff. Okay, that's what it comes down to we're gon na even abbreviate. The intro just helps you remember some stuff in today's episode is about five things.

To consider when doing a maintenance on a commercial package unit or at least a light commercial package unit, because some packaged units can get pretty big, there's some similarities and maybe some differences depending on tonnage and brand. But we're gon na go over five things. We're not gon na go over everything, just five things, all right so chill, but first I want to thank our great sponsors carrier, Mitsubishi, Electric cooling and heating. I also want to thank youi, I in the hub, smart kit, but also the wrs scales.

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Smart guy been in the trade a long time and he can help you find a technician. If your manager or an owner of a business so but now we're talking about five things to consider when maintaining a commercial package unit again, this isn't everything. This is just a list of things, especially if you're resi tech, you cut your teeth on resi. The way I did and then you find of doing some commercial.

These are things that you need to make sure that you don't forget, and you should have a more in-depth'less than this. You should fall what manufacturers say, but these are some things just to make sure you don't forget feels like I've mentioned this here we go. First thing is: is that I want you to wash fresh air filters if you are not thinking and if we say fresh air air is not always that fresh and Florida, it can actually be quite high humidity it's outdoor air, okay, but you need to make sure That, if it's got an outdoor hood, you've got an economizer you're, bringing an outdoor air. You need to make sure that you're washing those filters, don't let them get all gummed up.

That's fairly obvious. Some of them are like aluminum filters, but you got to make sure you wash them, don't forget to wash them. The next thing is one of the more disputed topics as far as how it should be done, and that is to check and adjust belt tension. A lot of texts will say: you want about half inch in deflection or one inch of deflection and then they'll kind of show you they're pinching fingers that varies quite a bit: tech to tech and so setting proper belt tension and adjusting it, making sure that they're Adjusted in each direction correctly is a very important part.

I'll tell you when I first started doing commercial maintenance. I had a couple big accounts at my first job and kind of got thrown into it. I would get belts far too tight because I didn't like them. Squealing right, and so when you get a belt too tight that results in high amperage on the blower blower motor, it usually leads to the belt breaking or throwing pretty soon thereafter stretching.

So the belt will just keep stretching the more you keep tightening it and excessive. Bearing wear and again it depends on the particular belt depends on particular equipment, but in many cases we're tightening belts when we really should be replacing them when they start getting worn down enough that you have to do significant amounts of tightening as it's wearing. It's probably time to replace it. Here's kind of my general rule of dull tension and there's a more accurate one that I'll cover, but you want the belt to be tight enough, that it doesn't slip at all or vibrate excessively, but no tighter.

So as tight as it needs to be, and no tighter a lot of newbies get belts too tight, the ones who look at the belt at all, so there's some who just totally ignore them, and then those tend to be too loose, but for the ones who Pay attention or trying to do a good job. They tend to get them too tight because they don't want the risk having a squeal, but that causes stress on the bearing stress on the motor. So the way I generally will say it is you want it to be tight enough, that it doesn't squeal or flop around, but no tie than that mini text. Again, like I mentioned, we'll talk about the half inch deflection rule, but that's just a guess.

That's no manufacturers going to tell you the half of the flexion rule. The best thing to do is to get a Browning belt tension tool and use that they've got great charts in with that tool. It's a very inexpensive tool. That'll show you how to do it and then, as you become more skilled and using it, you'll get a better feel for what proper tension is and what isn't again always follow manufacturer specs, but really in order to do a good job.

You're gon na need a tool to do it and there are several different tools, but the Browning belt tension tool is a nice inexpensive tool. Alright next thing number three on the list is to align police aligning police means that you need to make sure that the pulleys are in line with each other, and it's not the edge of the pulleys. A lot of people want to align the edges and again real quick. We need to define the difference in a pulley and a shiv spelled like sheave there's a lot of different opinions out there about what the difference is and if you look on Wikipedia it's different than the next site, you check most of time.

We will call it a sheave or Shiv if it's an adjustable pulley, so one where you can adjust how high the belt sits in it and we'll generally call that a shiv, that's sort of the term. That's used in the field most often, and so in some of those you can adjust them in order to produce more or less CFM. You definitely do not want to do that unless you know what you're doing. That's something that really only a professional really only if you're doing a test imbalance should you be adjusting that.

But the thing to know is, is that you'll often have pulleys and shifts that are of different widths, and so you have to line up the Centers of the police in order to make sure that you're not going to wear belts in an improper way. So that's an important thing make sure to get those pulleys aligned properly and it's not just a matter of getting the two pulleys aligned but making sure that the pulleys themselves are also square. If the motor mounts are out of square, then the pulleys will also be out of square. So you want to make sure that they're square, you can do all kinds of crazy stuff.

You can take strings and put it down the center and then measure to the edge. That's a method. You can use the old tried-and-true straightedge. Some people use fancy laser alignment tools, but really it comes down to having a good sense of square more than anything else.

I mean most of us are doing this sort of by sight, but again, if it's a long distance or you're having a hard time with it, you can use a string and measure off of a flat surface. You can use a straight edge. You can use the fancy lasers, it just depends on the particular application and how far the belt is, whether or not those things mean fine to be necessary, but it is important that you're making sure that everything is all square. The next thing is washing condenser coils properly and the reason why this can be tricky on some of these units.

This is also true of residential, but in commercial, especially a lot of times, you're gon na have to split the condenser coils, which means you're literally going to have to pull the coils apart and put it on something like a piece of wood or something. As you separate them and get in between the coils in order to get them properly cleaned, I know it sounds like a nightmare. Most of you probably haven't done it before it isn't as bad as it sounds, but it is a process whenever you have a split coil, coil. Well, there's two coils in one you're gon na tend to get stuff built up in between those two coils.

Now, how often it happens, it's gon na depend on the coil. It's gon na depend on how much stuff there is in the air, but you'd be shocked and how much crap can build up in between those coils. When you go to that system, that's got the high head pressure and I, like the cool, is clean. I don't know why it's so high.

I can bet you it's probably a split coil and there's a bunch of junk buildup in between it. So separating those coils apart and cleaning them well is a really big part of a commercial maintenance. If that's the situation that you've got, we have a video on our youtube channel that somebody did for us that I really appreciated that shows splitting and Washington condenser coil. So you can go look that up and that will help illustrate that better.

But it is something you need to definitely keep in mind. The final thing that you're gon na see whenever you get to three-phase equipment, is checking phase balance, and so, when you have imbalance in phases that can mean death to a motor, I mean it can cause all kinds of havoc. So in some cases, you're already gon na have a phase monitor in place. If you phase monitors in place, that's great so long as it's wired and set up properly, but keep in mind that if you have a phase balance of more than two percent, then that's going to cause some trouble and over four percent is like totally unacceptable.

And so we have a calculator for checking phase imbalance on the voltage side. So it's just a matter of checking the voltages in between all three legs. In most cases, they're going to be very similar within a volt or two and then that's acceptable. But it's when you start to see more than a volt or two of variation between the three legs.

That's when you want to check and see where you are and there's some math you can do because you're actually going to the average so you're, taking an average you're, seeing what their variation is between the farthest variations and the average. But if you go to the resources page on HVAC school HVAC, our school comm, we have calculators there and the voltage and balance calculators right there and the resources tab. So you can find that there. If you want to learn more about that.

But that's another thing to definitely check whenever you're working on any three-phase equipment is checking phase balance, and that's it that's the list of five, because this is a short podcast. I could come up with a lot of different things, but that is five items that I think you should think about, and I think you should check when you're doing a maintenance on a commercial piece of equipment, especially a commercial package unit. Thanks for listen to the podcast, thanks for all you do, you can check out all the other podcasts that we do by going to blue-collar roots, calm, that's blue-collar roots, calm and don't forget our friends over at true tech tools. Tr you tech tools, comm use the offer code, get schooled for a great discount and while you're there take a look at refrigeration technologies, products.

Alright have a great one. We'll talk to you next time on the HVAC school podcast.